Even if people have regained some weight several years after going on a
healthful Mediterranean or low-carbohydrate diet, they can enjoy lasting
beneficial effects, according to a follow-up study at Dimona’s Nuclear Research
Center and Ben-Gurion University of the Negev in Beersheba.

The study,
published last week as a peer-reviewed letter in the prestigious New England
Journal of Medicine, updates the landmark diet study carried out on 322
moderately obese personnel in the workplace over a period of two years, and
followed up four years after the end of the intervention. The original study was
called DIRECT, for Dietary Intervention Randomized Controlled Trial.

Dr.
Dan Schwarzfuchs of the Dimona center, where employees were put on diets and the
results observed, said: “Our follow- up subsequent data shows lasting, positive
effects of Mediterranean and low-carbohydrate diets six years later.”

BGU
researchers Dr. Iris Shai and Rachel Golan added: “Data from trials comparing
the effectiveness of weight-loss diets are frequently limited to the
intervention period. The results after four years suggests that the lipid
profile (lower cholesterol, triglycerides and arteriosclerosis) improved over
the long term, regardless of partial regain.”

The Mediterranean diet of
low meat intake and high consumption of vegetables, fruits, whole grains, pulses
and olive oil, as well as the low-carb diet, had a beneficial effect even though
the participants regained some weight. But people on a low-fat diet did not have
the same consistent and beneficial results.

Four years after the trial
was concluded, participants had regained an average of almost 2.7 kg. Since the
beginning of the trial, participants who followed the Mediterranean diet lost an
average of 3.1 kg., while those on the low-carb diet lost 1.7 kg. Thus the
Mediterranean diet was significantly more effective.

After four years
post-intervention, more than two-thirds (67 percent) of the DIRECT participants
had continued with their original assigned diet, 11% switched to another diet
and 22% were not dieting at all.

The researchers also found that after
six years, the highdensity lipoprotein (HDL or “good cholesterol”)/low-density
lipoprotein (LDL or “bad cholesterol”) ratio remained significantly lower only
in the low-carbohydrate diet. Triglyceride (another potential harmful blood fat)
levels remained significantly lower in the Mediterranean and low-carbohydrate
diets.

The researchers are now performing a new long-term dietary
intervention trial that targets weight-loss mechanisms relating to other
different dietary strategies, including novel techniques.